Research On Friction Compensation Of Servo System Based On Improved Auto-disturbance Rejection Controller

Servo control is commonly used in various control systems for civil and industrial applications,realizing high-efficiency automation in production and processing.The friction in mechanical motion inevitably affects the performance of the servo system.Due to the non-linear and time-varying characteristics of friction,the traditional PID control method is difficult to solve the problem of friction interference.With the continuous improvement of control performance requirements in various industries,it is of great theoretical and practical significance to apply modern control theory to design friction compensation controllers and improve the dynamic performance of servo systems.Auto disturbance rejection control technology can accurately observe and quickly compensate for various total disturbances of the controlled object,and has received extensive attention in the field of servo control.However,the design of classic auto disturbance rejection controller requires many tuning parameters,and there is no perfect method and theory for tuning parameters.This problem affects its engineering and practical applications.This paper presents an improved auto disturbance rejection controller,which can reduce the complexity of parameter setting during controller design.The main research contents are as follows:(1)Introduce the DC motor servo system,analyze the different friction forces and their characteristics,give the commonly used friction model,select the friction model to add disturbance to the servo system,and analyze the impact and cause of the friction force on the servo system through simulation,And gives specific measures to improve the performance of the servo system through feedback friction interference.(2)Aiming at the problem of complex parameter tuning of classic auto disturbance rejection controller,a variable gain differentiator is proposed to replace the expanded state observer in classic auto disturbance rejection controller,which reduces the complexity of parameter tuning and enhances The control system's ability to suppress noise is given,and the parameter tuning method of variable gain differentiator is given.(3)Through Matlab/Simulink simulation,simulation experiments were carried out on the three types of controllers,including the improved auto-rejection controller,PID controller and classic auto-rejection controller.The three controllers were compared and analyzed.Control system start,follow and anti-noise capabilities.The simulation results show that the improved auto disturbance rejection controller effectively compensates the friction interference of the servo system and improves the performance of the servo system.